Practical on which level? If you speak German there is https://www.springer.com/de/book/9783642111860 https://www.springer.com/de/book/9783642111860, one of the

Practical on which level? If you speak German there is https://www.springer.com/de/book/9783642111860 https://www.springer.com/de/book/9783642111860, one of the better books we used in university. It's not practical in a "how do I program with high level libraries" way, but it explains the crypto itself comprehensibly.